Mosasaurus was among the last of the mosasaurids, and among the largest. As with most mosasaurids, the legs and feet of Mosasaurus were modified into flippers, and the front flippers were larger than the hind flippers. This pin is held up with black rubber back done in beautiful black nickel.

Commemorate your sleepover at the Field Museum with this Dozin' with the Dinos Button Set. The soft-touch matte finish and weather-resistant steel pin-back make them perfect for accessorizing your jacket, hat, or backpack.